CN103698088A - Testing method for asymmetric rigidity of turbonator rotating shaft - Google Patents

Abstract

The invention discloses a testing method for the asymmetric rigidity of a turbonator rotating shaft. A testing device comprises an acceleration sensor (1), an impact hammer (2) and a dynamic signal analyzer (3). Firstly a data collection system is set; then the data collection system is connected with testing equipment; the impact hammer and the acceleration sensor are connected with the data collection system; the turbonator rotating shaft is laid on a balance test bed during measurement; the turbonator rotating shaft is provided with two large teeth and two small teeth which are distributed at an angle of 90 degrees; firstly one large tooth is upward; three sensors are arranged on the large tooth; the sensors are hammered through the impact hammer; hammering points are positioned at two ends of the rotating shaft; hammering and response signals are access to a dynamic signal analysis system; the signals are collected and analyzed through the dynamic signal analyzer, so as to obtain a frequency response function in the direction of the large tooth; then a rotor rotates 90 degrees, so as to ensure that the small teeth are upward. By adopting a measurement system, whether asymmetric rigidity of the turbonator rotating shaft exists can be tested; each tested vibration mode and critical speed of rotation have guiding effect on the dynamic balance test of the rotor.

Description

The method of testing of turbogenerator shaft asymmetric stiffness

Technical field:

The present invention relates to a kind of method of testing of testing turbogenerator shaft asymmetric stiffness.

Background technology:

Continuous increase along with turbodynamo capacity, rotor structure also becomes increasingly complex, two utmost point rotor of steam turbo generator bodies are due to the existence of wire casing, rigidity in canine tooth and little tooth direction is discrepant, when this differing greatly, in the time of will causing operation, rotor bow periodically-varied, can produce multiple-frequency vibration, to the transient equilibrium of rotor and generator actual motion, all can produce harmful effect.How accurately to measure turbogenerator shaft asymmetric stiffness the design of rotor, calculating and dynamic balance running are had to directive significance.

Summary of the invention:

The experimental measurement system and method that the object of this invention is to provide a kind of easy measurement, judgement turbogenerator shaft asymmetric stiffness.Technical scheme of the present invention is: the method for testing of measuring turbogenerator shaft asymmetric stiffness, proving installation is by acceleration transducer (1), impulsive force hammer (2) and dynamic signal analyzer (3) form, first data acquisition system (DAS) is arranged, a passage is hammering signal, three passages are acceleration signal, then joint test equipment, impulsive force hammer and acceleration transducer are received data acquisition system (DAS), during measurement, turbogenerator shaft is placed on balance test platform, turbogenerator shaft has two canine tooths and two little teeth, become 90 degree to distribute, it is canine tooth-little tooth-canine tooth-little tooth, first make one of them canine tooth upward, arrange three sensors in the above, firmly hammer carries out hammering, hammer point is at rotating shaft two ends, by hammering and response signal access dynamic signal analysis system, use dynamic signal analyzer that signal is gathered and analyzed, obtain the frequency response function of canine tooth direction, then make rotor 90 degree, make little tooth upward, repeat above-mentioned process, this method of testing comprises the steps:

1) adjust rotor-position, make rotating shaft canine tooth upward, three acceleration transducers are arranged on canine tooth vertically,

2) start department of computer science's data acquisition system (DAS) of unifying;

3) countershaft carries out hammering, and hammering direction is vertically downward, hammering at least 6 times, and by hammering signal and response signal access data acquisition system, signal analysis software gathers and analyzes data, obtains one group of frequency response function figure,

4) make rotating shaft 90-degree rotation, make the little tooth of rotating shaft upward, three acceleration transducers are arranged on little tooth vertically,

5) repeating step 3),

6) obtain two groups of frequency response functions are analyzed and processed, obtain the real figure frequently of frequency response function and empty figure frequently, minimum value or the empty maximal value of figure frequently by real figure are frequently determined natural frequency, obtain the natural frequency of canine tooth and little tooth both direction, the stiffness differences that can judge canine tooth and little tooth direction according to the size of natural frequency value, natural frequency is large, and rigidity is just large, natural frequency is little, and rigidity is just little.

The subject matter that the present invention will solve has:

1, use this measuring system can record turbogenerator shaft and whether have asymmetric stiffness;

2, each first order mode and the critical rotary speed that record have directive function to the dynamic balance running of rotor.

1. principle of work:

Two utmost point rotor of steam turbo generator bodies are due to the existence of wire casing, rigidity in canine tooth and little tooth direction is discrepant, when this differing greatly, rotor bow periodically-varied in the time of will causing operation, multiple-frequency vibration can be produced, to the transient equilibrium of rotor and generator actual motion, all harmful effect can be produced.The natural frequency of object depends primarily on its rigidity and quality, when mass conservation, natural frequency is directly proportional to its rigidity, so draw the natural frequency of rotor by Hammering Test and model analysis, can determine turbogenerator shaft whether have asymmetric stiffness by natural frequency value.

2. the course of work:

Turbogenerator shaft is placed on rotor balancing testing table, makes canine tooth orientation upward, along canine tooth, axially arranges respectively measuring point.Connect and start test macro, countershaft carries out hammering, and hammer point is at rotating shaft two ends, hammering and response signal are synchronously accessed to dynamic signal analysis system simultaneously, carry out signals collecting, then the signal gathering is carried out to model analysis, draw the natural frequency in canine tooth orientation.Then make rotor 90 degree, make little tooth orientation upward, along little tooth, axially arrange respectively measuring point, countershaft carries out hammering, hammer point, at rotating shaft two ends, synchronously accesses dynamic signal analysis system by hammering and response signal simultaneously, carries out signals collecting, then the signal gathering is carried out to model analysis, draw the natural frequency in little tooth orientation.According to the size of the natural frequency value of canine tooth and little tooth direction, can judge the stiffness differences of canine tooth and little tooth direction.

Turbogenerator shaft asymmetric stiffness can be tried to achieve by calculating, but result of calculation is sometimes not necessarily accurate.Traditional test rotating shaft asymmetric stiffness is by adding weight in rotating shaft middle, then surveys the flexural deformation of rotating shaft.But there are many problems in this method, be first the size that adds weight, strengthened, countershaft can produce harmful effect, has added little and has tested inaccurately, and whole process is very complicated, test is prepared and the process of the test several days time of needs just can complete, and wastes time and energy.Method of the present invention only need to be on rotor placement sensor, connect and startup test macro, then rotor is carried out to hammering, hammering 6 times just can, and then make rotor 90 degree, rearrange sensor, hammering is 6 times again, and dynamic signal analyzer can be processed in real time to hammering and response signal, and hammering finishes, measurement result just out, is normally done such test and is no more than 1 hour.Method of testing of the present invention is simple, and test result is accurate, can distinguish trickle stiffness differences.

Accompanying drawing explanation:

The test point position figure of Fig. 1 turbogenerator shaft asymmetric stiffness

The experimental measurement system chart of Fig. 2 turbogenerator shaft asymmetric stiffness

The real figure frequently of Fig. 3 frequency response function and empty figure frequently

Embodiment:

Experimental measurement system is comprised of following critical piece: acceleration transducer, impulsive force hammer and dynamic signal analyzer, as shown in Figure 2.First data acquisition system (DAS) is arranged, a passage is hammering signal, and three passages are acceleration signal, joint test equipment then, and impulsive force hammer and acceleration transducer are received data acquisition system (DAS).During measurement, turbogenerator shaft is placed on balance test platform, and turbogenerator shaft has two canine tooths and two little teeth, becomes 90 degree to distribute, i.e. canine tooth-little tooth-canine tooth-little tooth.Test altogether two operating modes, operating mode 1: make one of them canine tooth upward, arrange three sensors in the above, as shown in Figure 1, survey the natural frequency of vertical direction, firmly hammer carries out hammering, hammer point is at rotating shaft two ends, by hammering and response signal access dynamic signal analysis system, use dynamic signal analyzer that signal is gathered and analyzed, obtain the frequency response function of canine tooth direction.Operating mode 2: make rotor 90 degree, make little tooth upward, repeat above-mentioned process, this method of testing comprises the steps:

1) as shown in Figure 1, adjust rotor-position, make rotating shaft canine tooth upward, three acceleration transducers 1 are arranged on canine tooth vertically,

2) start department of computer science's data acquisition system (DAS) of unifying;

3) countershaft carries out hammering, and as shown in Figure 1, hammering direction is vertically downward to hammer point 2, hammering at least 6 times, as shown in Figure 2, by hammering signal and response signal access data acquisition system, signal analysis software gathers and analyzes data, obtains one group of frequency response function figure

4) sensing station as shown in Figure 1, makes rotating shaft 90-degree rotation, makes the little tooth of rotating shaft upward, and three acceleration transducers are arranged on little tooth vertically,

5) repeating step 3),

6) obtain two groups of frequency response functions are analyzed and processed, obtain the real figure frequently of frequency response function and empty figure frequently, as shown in Figure 3, minimum value or the empty maximal value of figure frequently by real figure are frequently determined natural frequency, obtain the natural frequency of canine tooth and little tooth both direction, can judge the stiffness differences of canine tooth and little tooth direction according to the size of natural frequency value, natural frequency is large, rigidity is just large, and natural frequency is little, and rigidity is just little.

Test of the present invention uses result to prove:

This method of testing, can judge easily and efficiently turbogenerator shaft and whether have asymmetric stiffness, and can accurately measure each first order mode and the critical rotary speed of rotating shaft, for rotating shaft designs, calculating and dynamic balance running provide reliable basis.This measuring system is simple, measurement is accurate, it is easy to judge.

Claims (1)

1. a method of testing of measuring turbogenerator shaft asymmetric stiffness, it is characterized in that: proving installation is by acceleration transducer (1), impulsive force hammer (2) and dynamic signal analyzer (3) form, first data acquisition system (DAS) is arranged, a passage is hammering signal, three passages are acceleration signal, then joint test equipment, impulsive force hammer and acceleration transducer are received data acquisition system (DAS), during measurement, turbogenerator shaft is placed on balance test platform, turbogenerator shaft has two canine tooths and two little teeth, become 90 degree to distribute, it is canine tooth-little tooth-canine tooth-little tooth, first make one of them canine tooth upward, arrange three sensors in the above, firmly hammer carries out hammering, hammer point is at rotating shaft two ends, by hammering and response signal access dynamic signal analysis system, use dynamic signal analyzer that signal is gathered and analyzed, obtain the frequency response function of canine tooth direction, then make rotor 90 degree, make little tooth upward, repeat above-mentioned process, this method of testing comprises the steps:

1) adjust rotor-position, make rotating shaft canine tooth upward, three acceleration transducers are arranged on canine tooth vertically;

2) start department of computer science's data acquisition system (DAS) of unifying;

3) countershaft carries out hammering, and hammering direction is vertically downward, hammering at least 6 times, and by hammering signal and response signal access data acquisition system, signal analysis software gathers and analyzes data, obtains one group of frequency response function figure;

4) make rotating shaft 90-degree rotation, make the little tooth of rotating shaft upward, three acceleration transducers are arranged on little tooth vertically;

5) repeating step 3);

6) obtain two groups of frequency response functions are analyzed and processed, obtain the real figure frequently of frequency response function and empty figure frequently, minimum value or the empty maximal value of figure frequently by real figure are frequently determined natural frequency, obtain the natural frequency of canine tooth and little tooth both direction, the stiffness differences that can judge canine tooth and little tooth direction according to the size of natural frequency value, natural frequency is large, and rigidity is just large, natural frequency is little, and rigidity is just little.

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